<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: FeedAbstract.php 23953 2011-05-03 05:47:39Z ralph $
 */

/**
 * @see Zend_Feed_Reader
 */
require_once 'Zend/Feed/Reader.php';

/**
 * @see Zend_feed_Reader_FeedInterface
 */
require_once 'Zend/Feed/Reader/FeedInterface.php';

/**
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
abstract class Zend_Feed_Reader_FeedAbstract implements Zend_Feed_Reader_FeedInterface {
	/**
	 * Parsed feed data
	 *
	 * @var array
	 */
	protected $_data = array ();
	
	/**
	 * Parsed feed data in the shape of a DOMDocument
	 *
	 * @var DOMDocument
	 */
	protected $_domDocument = null;
	
	/**
	 * An array of parsed feed entries
	 *
	 * @var array
	 */
	protected $_entries = array ();
	
	/**
	 * A pointer for the iterator to keep track of the entries array
	 *
	 * @var int
	 */
	protected $_entriesKey = 0;
	
	/**
	 * The base XPath query used to retrieve feed data
	 *
	 * @var DOMXPath
	 */
	protected $_xpath = null;
	
	/**
	 * Array of loaded extensions
	 *
	 * @var array
	 */
	protected $_extensions = array ();
	
	/**
	 * Original Source URI (set if imported from a URI)
	 *
	 * @var string
	 */
	protected $_originalSourceUri = null;
	
	/**
	 * Constructor
	 *
	 * @param DomDocument The DOM object for the feed's XML
	 * @param string $type Feed type
	 */
	public function __construct(DomDocument $domDocument, $type = null) {
		$this->_domDocument = $domDocument;
		$this->_xpath = new DOMXPath ( $this->_domDocument );
		
		if ($type !== null) {
			$this->_data ['type'] = $type;
		} else {
			$this->_data ['type'] = Zend_Feed_Reader::detectType ( $this->_domDocument );
		}
		$this->_registerNamespaces ();
		$this->_indexEntries ();
		$this->_loadExtensions ();
	}
	
	/**
	 * Set an original source URI for the feed being parsed. This value
	 * is returned from getFeedLink() method if the feed does not carry
	 * a self-referencing URI.
	 *
	 * @param string $uri
	 */
	public function setOriginalSourceUri($uri) {
		$this->_originalSourceUri = $uri;
	}
	
	/**
	 * Get an original source URI for the feed being parsed. Returns null if
	 * unset or the feed was not imported from a URI.
	 *
	 * @return string|null
	 */
	public function getOriginalSourceUri() {
		return $this->_originalSourceUri;
	}
	
	/**
	 * Get the number of feed entries.
	 * Required by the Iterator interface.
	 *
	 * @return int
	 */
	public function count() {
		return count ( $this->_entries );
	}
	
	/**
	 * Return the current entry
	 *
	 * @return Zend_Feed_Reader_EntryInterface
	 */
	public function current() {
		if (substr ( $this->getType (), 0, 3 ) == 'rss') {
			$reader = new Zend_Feed_Reader_Entry_Rss ( $this->_entries [$this->key ()], $this->key (), $this->getType () );
		} else {
			$reader = new Zend_Feed_Reader_Entry_Atom ( $this->_entries [$this->key ()], $this->key (), $this->getType () );
		}
		
		$reader->setXpath ( $this->_xpath );
		
		return $reader;
	}
	
	/**
	 * Get the DOM
	 *
	 * @return DOMDocument
	 */
	public function getDomDocument() {
		return $this->_domDocument;
	}
	
	/**
	 * Get the Feed's encoding
	 *
	 * @return string
	 */
	public function getEncoding() {
		$assumed = $this->getDomDocument ()->encoding;
		if (empty ( $assumed )) {
			$assumed = 'UTF-8';
		}
		return $assumed;
	}
	
	/**
	 * Get feed as xml
	 *
	 * @return string
	 */
	public function saveXml() {
		return $this->getDomDocument ()->saveXml ();
	}
	
	/**
	 * Get the DOMElement representing the items/feed element
	 *
	 * @return DOMElement
	 */
	public function getElement() {
		return $this->getDomDocument ()->documentElement;
	}
	
	/**
	 * Get the DOMXPath object for this feed
	 *
	 * @return DOMXPath
	 */
	public function getXpath() {
		return $this->_xpath;
	}
	
	/**
	 * Get the feed type
	 *
	 * @return string
	 */
	public function getType() {
		return $this->_data ['type'];
	}
	
	/**
	 * Return the current feed key
	 *
	 * @return unknown
	 */
	public function key() {
		return $this->_entriesKey;
	}
	
	/**
	 * Move the feed pointer forward
	 *
	 */
	public function next() {
		++ $this->_entriesKey;
	}
	
	/**
	 * Reset the pointer in the feed object
	 *
	 */
	public function rewind() {
		$this->_entriesKey = 0;
	}
	
	/**
	 * Check to see if the iterator is still valid
	 *
	 * @return boolean
	 */
	public function valid() {
		return 0 <= $this->_entriesKey && $this->_entriesKey < $this->count ();
	}
	
	public function getExtensions() {
		return $this->_extensions;
	}
	
	public function __call($method, $args) {
		foreach ( $this->_extensions as $extension ) {
			if (method_exists ( $extension, $method )) {
				return call_user_func_array ( array ($extension, $method ), $args );
			}
		}
		require_once 'Zend/Feed/Exception.php';
		throw new Zend_Feed_Exception ( 'Method: ' . $method . 'does not exist and could not be located on a registered Extension' );
	}
	
	/**
	 * Return an Extension object with the matching name (postfixed with _Feed)
	 *
	 * @param string $name
	 * @return Zend_Feed_Reader_Extension_FeedAbstract
	 */
	public function getExtension($name) {
		if (array_key_exists ( $name . '_Feed', $this->_extensions )) {
			return $this->_extensions [$name . '_Feed'];
		}
		return null;
	}
	
	protected function _loadExtensions() {
		$all = Zend_Feed_Reader::getExtensions ();
		$feed = $all ['feed'];
		foreach ( $feed as $extension ) {
			if (in_array ( $extension, $all ['core'] )) {
				continue;
			}
			$className = Zend_Feed_Reader::getPluginLoader ()->getClassName ( $extension );
			$this->_extensions [$extension] = new $className ( $this->getDomDocument (), $this->_data ['type'], $this->_xpath );
		}
	}
	
	/**
	 * Read all entries to the internal entries array
	 *
	 */
	abstract protected function _indexEntries();
	
	/**
	 * Register the default namespaces for the current feed format
	 *
	 */
	abstract protected function _registerNamespaces();
}
